Fig. 3

Determination of redox state by imaging of HP [1-13C] ascorbate (VitC) and [1-13C] dehydroascorbate (DHA). Oxidative stress caused by ROS (1.) can be alleviated by oxidation of ascorbate to DHA (2.), and recycling of DHA to ascorbate can occur indirectly with oxidation of glutathione (3.) or directly with oxidation of NADH (4.). The ratio of [ascorbate] to [DHA] has been successfully used in mice models as a biomarker to determine pH in vivo. Adapted with permission from ref. [62]